Properties of Microorganisms contributing to the Sensory Properties and Health Benefits of Fermented Food

Abstract:

Fermentation of food has been known as a means to preserve goods since the medieval ages in order to ensure sufficient food supply during unfavorable times. Fermented food during the modern times has been widely studied for its health benefits and the microorganisms that are involved in its fermentation process. The most common fermented food products known, especially wine, cheese and kimchi, have been studied to better understand the microorganisms that are involved in transforming a simple food to a good that enhance the sensory properties of the food as well as contributing to the health benefits of the food.

Introduction:

Fermented food products, such as wine, cheese and kimchi, existed since the medieval ages as a way for commoners to preserve food and to ensure that there are sufficient food supplies during unfavorable times. These days fermented food products are viewed as food with unique flavors that are known to enhance sensory experiences. Besides that, fermented food products, such as wine, cheese and kimchi, are known, not just for the extra sensory properties that it provides but also the different health benefits that resulted from its fermentation process. Fermentation is a process that converts carbohydrates into sugars under anaerobic conditions, via the metabolic activities of microorganisms, i.e. yeast and bacteria. Through the activities of these microorganisms, food products last longer, as well as possess enhancements in flavor. In this review paper, the properties of some of the common microorganisms that are present in fermented food products, specifically wine, cheese and kimchi, will be studied based on the aspects of how the metabolic activities of these microorganisms contributes to the sensory properties, i.e. texture, smell, taste and etc, as well as the health benefits that fermentation of these food products have contributed.

Wine

Wine is an alcohol beverage that is made from grapes through the process of fermentation which involves various types of yeast and bacteria. The process of winemaking can be dated back to centuries but the process of winemaking itself has never been studied until the early 21st century. The types of wine that is being made depends on the types of grapes used, the types of natural yeast present and the type of yeast added, as well as, the environmental conditions in which the grapes are grown. In addition, the types of terrains, regions and conditions also determines the type of wine that the grapes are able to produce. Besides that, the type of yeasts and bacteria present in the grapes or added to the grape mainly plays an important role in contributing to the aroma, flavor, texture and viscosity, and color of the wine. 

Health Benefits 

Wine has been known to contain various components that bring health benefits when consumed. Wine is known to contain antioxidants, known as phenolic compounds, that exist in various different forms. These antioxidants function as free-radical scavengers that are responsible for neutralizing ROS(Reactive Oxygen Species) that are the main cause of oxidative stress and can damage biological structures of the cells, as well as interfere with cell signaling by altering the cellular redox status or by participating in the intracellular signaling themselves. In addition, they are also responsible for enhancing the endogenous antioxidant capacity of cells/tissues or influencing the signaling pathways by interaction with cellular receptors and enzymes. 

Cheese 

Cheese is also another fermented food that is incorporated into many cuisines and is part of the traditional food in countries, such as Europe. Cheese is a fermented food that is mainly made from milk that is drained, in order to yield concentrated milk proteins, fats and other constituents that are responsible for the flavor and aroma of the cheese. The process of cheese making includes processes such as milking, fermentation, coagulation, curd cutting, pressing or draining, ripening and packaging and distribution. 

Health Benefits 

Cheese is a type of fermented food that is considered a good source of essential nutrients, such as proteins, peptides, amino acids, short-, medium- and long- chain fatty acids, vitamins and essential minerals, as well as probiotic bacteria. The nutritional components of a cheese depends on several factors that includes the type of milk that is used to make the cheese, lactation period, ripening process and type of starter culture used. During the cheese making process, water soluble vitamins are extensively lost, however, some water soluble vitamins are found to have remained in the cheese even after making the cheese, which includes niacin, folate and vitamin B12. 

Kimchi 

Kimchi is a traditional fermented vegetable that is widely associated with Korea, and the most commonly known kimchi variety is the cabbage kimchi (also known a baechu kimchi), that is made from mainly Chinese cabbage. There are also other varieties of kimchi that are made from other vegetables, which includes radish, cucumber, leek, mustard leaf and green onion, and these variations are dependent on the main ingredient used, region, seasons and methods of preparations. 

Health Benefits

Kimchi has also been reported to be anticancer, antioxidant, antiartherosclerotic, antidiabetic and antiobese. The raw ingredients that are used to make kimchi contain great amounts of vitamins, minerals, dietary fibers and other functional components that are derived from bioactive compounds in the raw ingredients.  The yellow-green vegetables that were used to prepare kimchi are shown to have preventive abilities against cancer, improve immunity, delay the aging process and prevent constipation. 

Conclusions:

Microorganisms play a role in the fermenting process, allowing food to have a longer shelf-life, as well as contributing to the sensory properties of the fermented food and its health benefits. The process of fermentation with these microorganisms, especially LAB that is present in most fermented foods, allows the breakdown of certain components that brings health benefits to consumers and at the same time, also provides certain sensory properties that allows the consumers to enjoy the fermented food products. Furthermore, certain LAB species have also been known to be probiotic bacteria, which further increase the health benefit values of these fermented food products. Despite the health benefits that each of the reviewed fermented food possess, there are also some drawbacks that comes with consuming too much of the fermented food products, such as wine, due to its alcohol contents, and cheese, due to the amount of unsaturated fatty acids that certain types of cheeses contains. Although fermented food is considered a form of functional food, due to the wide range of health benefits that it possesses, the consumption of fermented food should also be in moderation and incorporated together with other types of healthy food in order to bring out the most of its health benefits.

Written by Cayden Po